There are many applications where safe refueling of vehicles or other fuel recipients is required. For example, the Applicant is developing fuel cell power supply systems suitable for use in non-road electric lift vehicles and the like. As described in a continuation (namely application Ser. No. 10/684,622) of Applicant's application Ser. No. 09/785,878, the disclosure of which is hereby incorporated by reference, Applicant's power supply systems are sized to replace conventional electric vehicle traction batteries. Although such systems have a much improved operating range in comparison to conventional battery systems, they must be periodically refueled. This requires safe and reliable systems for transferring hydrogen or reformable hydrocarbon fuels to the vehicle power supply.
Many non-road lift vehicles, such as forklift trucks and the like, operate in indoor environments such as warehouses and product storage/distribution facilities. The need to refuel fuel cell powered vehicles and the like indoors poses particular challenges. Indoor refueling is generally not permitted under fire codes except for a very few restricted applications, such as vehicle manufacturing plants and specially designed airplane hangers. This is due to the fact that safety risks are greatly increased since indoor environments do not allow for the natural dispersion of hazardous or flammable gases and liquids. Moreover, indoor environments often provide an ample supply of combustible materials.
Improved systems for ensuring safe refueling of vehicles utilizing hydrogen or other hazardous or flammable fuels are therefore required. Such systems should preferably include means for immobilizing the recipient vehicle during fueling sessions, means for reducing the risk of spark generation and fuel ignition, and means for automatically ending fueling in the case of fuel leaks or other system failures. The refueling systems must also be user-friendly so that they can be successfully and reliably implemented by vehicle operators who may not necessarily be familiar with refillable electro-chemical power generation systems.
Some dispenser systems for preventing unauthorized fueling of a vehicle or the like are known in the prior art. U.S. patent application Ser. No. 10/296,232, Hirakata, published 17 Jul. 2003 under publication No. US 2003/0134167 A1 describes a fuel cell fuel supply system for an electric vehicle. The system includes a hydrogen supply device which is connectable to a connector receptor of the vehicle's fuel tank. The connector receptor may include a lid for covering the connector receptor. When the system determines that the fuel cells are in a working state, the system prevents opening of the fuel lid, thus preventing refueling of the vehicle while the fuel cells are operational. When the system determines that the fuel cells are not operating, refueling of the vehicle is permitted. The hydrogen supply device may include a controller for transmitting control signals to and from a controller of the electric vehicle when the hydrogen supply is connected to the hydrogen inlet of the vehicle. The system also prevents movement of the vehicle (by disabling the fuel cells or any secondary battery) when the fuel lid is open, thus enhancing the safety of hydrogen supply.
While the Hirakata invention does include means for immobilizing the electrical vehicle during refueling, it does not include means for automatically terminating refueling in the case of a fuel leak or other similar system failure. Moreover, Hirakata does not describe an interlock for lockably coupling the hydrogen supply to the vehicle hydrogen inlet.
U.S. Pat. Nos. 6,522,947 and 6,466,842, Hartsell, dated 15 Oct. 2002 and 18 Feb. 2003 respectively, relate to a dispenser system for preventing unauthorized refueling of vehicles. The dispenser includes a receiver capable of receiving fuel delivery indicia transmitted from the vehicle, such as vehicle type, vehicle identity, diagnostics and the like. The dispenser is configured to end fuel dispensing if an improper fueling condition is identified.
U.S. Pat. No. 5,159,523, Claassen et al., relates to a grounding system and detection circuit for fueling aircraft or other mobile vehicles. The system prevents operation of a fuel dispensing system unless a proper grounding configuration is observed.
U.S. Pat. No. 6,497,363, Kelrich, issued 24 Dec. 2002 relates to an electrical connector with identification chip for use with vehicle refueling systems. According to this system the vehicle communicates with a refueling station separate from the vehicle through a fuel nozzle communicator arranged adjacent a fuel intake conduit of the vehicle.
U.S. Pat. No. 5,720,327, Foster, relates to a vehicle safety fueling system. The system includes a solenoid valve which disables the engine ignition system when a dispensing nozzle is placed within a vehicle fueling port. The Foster invention prevents accidental driving off with the vehicle from a fuel pump without first removing a fuel dispensing nozzle from the tank of the vehicle. According to the Foster invention a proximity switch, electrically connectable to the vehicle's starter, is located adjacent the inlet spout of the vehicle fuel tank.
U.S. Pat. No. 09/848,493, Jin et al., published under No. 2002/0162601 A1 dated 7 Nov. 2002, relates to a safety system for fueling vehicles which includes the generation of a vehicle confirmation signal which is transmitted from the vehicle to be filled to a fueling station. The system further includes a dispenser activation system responsive to the vehicle confirmation signal for activating dispensing of fuel through a fuel nozzle and a vehicle locking system to disable the vehicle while the vehicle fuel door is open or when the fueling nozzle is attached to the vehicle nozzle receptacle. The system may also include an emergency power off circuit to provide power to detection and alarm systems, such as fuel vapor detectors, malfunction alarms and active ventilation systems.
While various systems are known in the prior art for regulating transfer of fuel from a fueling station to a recipient vehicle or the like, none of the prior art include a combination of interlocks and other safety features which prevent refueling until multiple safety criteria are satisfied. The need has therefore arisen for improved fueling systems and methods designed to minimize or negate the risk that hazardous and/or flammable products could be exposed to the atmosphere during a fueling session. A particular need has arisen for fuel dispensing systems and methods specifically adapted for high-risk indoor environments.